One of Japan’s best-loved snack brands is switching to monochrome packaging for a number of its products due to a shortage of naphtha – a crude-oil derivative used in petrochemicals and printing inks – caused by the closure of the Strait of Hormuz.

In a statement issued on Tuesday, Calbee said it would “temporarily revise packaging specifications for certain products in response to supply instability affecting certain raw materials amid ongoing tensions in the Middle East”.

The decision by the leading potato crisp manufacturer is a telling signal to consumers of how the stalemated conflict involving the US, Israel and Iran is affecting daily life in Japan.

The closure of the Strait of Hormuz to shipping since early March is being felt around the world. About a fifth of global oil consumption normally passes through the waterway.

On Monday, Japanese Prime Minister Sanae Takaichi said the government had been able to access other sources to secure sufficient crude oil supplies to meet domestic demand for the foreseeable future.

At a meeting of the Upper House Audit Committee, and in response to a question from an opposition politician calling for the government to impose restrictions on energy use, Takaichi said there was no need to instruct the public to limit consumption.